1. Field of the Invention
The present invention relates to a liquid crystal display device. More particularly, the present invention relates to a backlight driving system for a liquid crystal display device that does not include a color filter.
2. Description of the Related Art
Recently, as personal computers, televisions, and the like become lighter and thinner, a display device for use in such devices has also been demanded to be lighter and thinner. To meet such demands, flat panel displays (FPDs), such as liquid crystal displays (LCDs), have been developed to replace cathode ray tubes (CRTs).
An LCD device is a FPD obtaining a desired image signal by applying electric field to a liquid crystal, having an anisotropic dielectric constant, between two substrates, and controlling the amount of light transmitted from an external light source (a backlight unit) to the substrates by controlling the intensity of the electric field.
In general, a conventional LCD device displays color images using a color filter scheme. The color filter scheme may include providing a color filter layer for each of the three primary colors, i.e., red R, green G and blue B, on one of two substrates. In transmitting light from a single light source into the R, G and B color filter layers, the LCD device may display a desired color by controlling the amount of light transmitted into the R, G and B color filter layers, and compositing the R, G and B colors.
However, the conventional LCD device using such a color filter scheme may have a number of disadvantages. For example, since the light transmittance of the color filter is a maximum of about 33% or less, loss of light output from the color filter is significant, thereby decreasing brightness. In order to increase brightness, a backlight unit should be made brighter, thereby increasing power consumption. Finally, the color filter is very expensive compared with other parts of the LCD device, thereby increasing production cost.